Overview - ISO 6033:1983 (Projection reel size 7 for 8 mm Type S)
ISO 6033:1983 specifies the dimensions and functional requirements for projection reels size 7 used with 8 mm Type S motion‑picture film. The size‑7 reel has a nominal capacity of 15 m (for 0.1 mm film thickness), fits Type S encapsulated projection cassettes that accept reels with up to 75 mm maximum outside flange diameter, and is also compatible with normal reel‑to‑reel projection equipment. The standard defines hub and flange geometry, film attachment and retention requirements, allowable run‑out tolerances and guidance for winding and drive features.
Key topics and technical requirements
- Nominal capacity and film thickness: Size 7 designed for ~15 m of 8 mm Type S film of 0.1 mm thickness (table examples provided for varying total film thickness including magnetic track).
- Interchangeability: Compatible with all 8 mm Type S projection cassettes accepting reels up to 75 mm flange diameter; also fits reel‑to‑reel projectors.
- Retention strength: Film retention means (plug/clip) must hold the film so that a minimum radial traction of 5 N will not tear off the reel hub.
- Flange design: At least one solid flange (no thread‑up slots) is required; the solid flange must be opposite the access/opening for film attachment.
- Dimensional tolerances: Radial and lateral run‑out maxima are specified (figures/tables) to ensure free spinning and avoid film damage; manufacturers must observe these tolerances.
- Capacity calculation: The standard provides a method (variables defined for winding diameter, maximum hub diameter and film thickness) to calculate reel capacity for different winding tightness.
- Retention plug/clip limits: If plugs or clips are used, they must not protrude beyond specified dimensions so as not to interfere with cassettes or projection mechanisms.
- Drive features: Three drive slots on the spindle hole of each flange are specified to help loading and rewinding.
Applications and who uses it
- Reel and cassette manufacturers - ensure mechanical compatibility and interchangeability across projectors and labs.
- Projection equipment designers - design cassette cavities, spindle drives and clearance to comply with run‑out and retention dimensions.
- Film processing laboratories and rental houses - use standardized reels for returning processed 8 mm film safely.
- Archives, restorers and museums - preserve handling standards and select compatible reels for playback and storage.
- Technicians and suppliers - verify retention strength, winding practices (film threaded clockwise, emulsion out) and drive slot alignment.
Related standards
- ISO 1700 - 8 mm Type S raw stock cutting and perforating dimensions
- ISO 3639 - Projection reels/spools 75 to 312 mm - dimensions and specifications
- ISO 3653 (spindles) - spindles for 8 mm Type S projection reels/spools
Keywords: ISO 6033:1983, projection reel size 7, 8 mm Type S, film reel dimensions, cinematography standard, projection cassette, reel‑to‑reel compatibility.
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